The United States scored four times in the first period and defeated Finland 4-2 on Thursday at the Women's World Championships at Scotiabank Place in Ottawa.
Monique Lamoureux had the first and last goals in the big first period. Brianna Decker and Amanda Kessel also scored for the Americans, who were coming off a 3-2 shootout loss to Canada on Tuesday.
"Finland competed hard and made it a great game but we're glad to have our first win under our belt," coach Katey Stone told USA Hockey's website. "We're looking forward to building on our game."
Finland (1-1-0, 3 points) scored on their only shot of the first period and added another goal in the second to cut the deficit to two goals. But the United States (1-0-1, 4 points) controlled the third period, outshooting Finland 20-4.
Brianne McLaughlin stopped 11 of 13 shots in her first start of the tournament.
The U.S. continues round-robin play against Switzerland on Friday. Canada beat Switzerland 13-0 on Wednesday night. Marie-Philip Poulin scored four goals to tie the Canadian record for most goals by one player in a Women's World Championship game -- and the first since 1994.
In Group B, Russia improved to 2-0-0 by beating the Czech Republic 3-1.
Yekaterina Lebedeva scored a power-play goal early in the first period, and Yekaterina Lebedeva added another in the second to make it 2-0. Denisa Krizova cut the deficit to 2-1 late in the second period, but a shorthanded goal by Tatyana Burina in the third period put the game away.
Germany, a 4-0 loser to Russia in its opener, was outshot 33-11 by Sweden but took the game into overtime before losing 3-2.